Re: [PATCH] sh: time: Remove the read_persistent_clock()

[Arnd Bergmann <arnd@arndb.de>]

On Thu, Apr 19, 2018 at 8:06 AM, Baolin Wang <baolin.wang@linaro.org> wrote:
> The read_persistent_clock() uses a timespec, which is not year 2038 safe
> on 32bit systems. Moreover on sh platform, we have RTC drivers that can
> be used to compensate the system suspend time. Thus we can remove the
> read_persistent_clock() safely.
>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

Hi Baolin and sh maintainers.

I have done a similar patch but never got around to posting it. Please
see my patch below.

Note that the patch is whitespace broken, I can send a proper
version to the sh maintainers if they want to merge it, or I can
apply my patch to my y2038 tree myself.

       Arnd

commit cade6829ca223d9761863e74595d677b3dc14ecd
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Wed Jan 24 16:18:50 2018 +0100

    sh: remove unused rtc_sh_get/set_time infrastructure

    All platforms are now converted to RTC drivers, so this has become
    obsolete. The board_time_init() callback still has one caller, but
    could otherwise also get killed.

    This removes one more usage of the deprecated timespec structure,
    which overflows in y2038.

    Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/sh/include/asm/rtc.h b/arch/sh/include/asm/rtc.h
index c63555ee1255..fe55fbb181aa 100644
--- a/arch/sh/include/asm/rtc.h
+++ b/arch/sh/include/asm/rtc.h
@@ -4,8 +4,6 @@

 void time_init(void);
 extern void (*board_time_init)(void);
-extern void (*rtc_sh_get_time)(struct timespec *);
-extern int (*rtc_sh_set_time)(const time_t);

 #define RTC_CAP_4_DIGIT_YEAR   (1 << 0)

diff --git a/arch/sh/kernel/time.c b/arch/sh/kernel/time.c
index fcd5e41977d1..eb0a91270499 100644
--- a/arch/sh/kernel/time.c
+++ b/arch/sh/kernel/time.c
@@ -22,75 +22,6 @@
 #include <asm/clock.h>
 #include <asm/rtc.h>

-/* Dummy RTC ops */
-static void null_rtc_get_time(struct timespec *tv)
-{
-       tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
-       tv->tv_nsec = 0;
-}
-
-static int null_rtc_set_time(const time_t secs)
-{
-       return 0;
-}
-
-void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
-int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
-
-void read_persistent_clock(struct timespec *ts)
-{
-       rtc_sh_get_time(ts);
-}
-
-#ifdef CONFIG_GENERIC_CMOS_UPDATE
-int update_persistent_clock(struct timespec now)
-{
-       return rtc_sh_set_time(now.tv_sec);
-}
-#endif
-
-static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
-{
-       struct timespec tv;
-
-       rtc_sh_get_time(&tv);
-       rtc_time_to_tm(tv.tv_sec, tm);
-       return 0;
-}
-
-      &rtc_generic_ops,
-      sizeof(rtc_generic_ops));
-
-
- return PTR_ERR_OR_ZERO(pdev);
-}
-device_initcall(rtc_generic_init);
-
 void (*board_time_init)(void);

 static void __init sh_late_time_init(void)